0 -> 1 
1 -> 11 
2 -> 21 
3 -> 1211 
4 -> 111221 
5 -> 312211 
6 -> 13112221 
7 -> 1113213211 
8 -> 31131211131221 
9 -> 13211311123113112211 
10 -> 11131221133112132113212221 